scholarly journals Simulation Study of Ignition Characteristics of Impinging Sprays in Constant Volume Chamber

2021 ◽  
Vol 23 (04) ◽  
pp. 70-81
Author(s):  
Sanaur Rehman ◽  
◽  
Shah Shahood Alam ◽  
Keyword(s):  
Surface Temperature ◽  
Simulation Study ◽  
Ignition Delay ◽  
Injection Pressure ◽  
Delay Period ◽  
Constant Volume ◽  
Operating Conditions ◽  
Air Pressure ◽  
Hot Surface ◽  
Ignition Delay Period

The present study involves the simulation of a constant volume, non-premixed, hot surface spray combustion of diesel fuel for a given set of injection pressure, compressed air pressure (cylinder air pressure) and hot surface temperature (hot plate temperature) and their effects on ignition delay period. Fuel injection pressure was varied from 100 bar – 300 bar in steps of 100 bar, cylinder air pressure in the range of 20 bar to 40 bar (in steps of 10 bar) and hot surface temperature from 623 K to 723 K (50 K steps). The problem was solved using 2D axisymmetric geometry. A structured mesh of about 1.24 lac nodal points was created and tested for grid independency. For solving flow behavior, a pressure solver was used with a turbulence model of k-ε with enhanced wall functions. While a volumetric eddy dissipation model was used to solve combustion phenomena. Ignition delay period was calculated with the help of static temperature versus time plot. It is found that keeping any two operating parameters constant, third operating parameter is inversely proportional to ignition delay period. The results of the present simulation study are in a fairly good agreement with the experimental studies at same operating conditions.

scholarly journals Improvement in Ignition Delay Characteristics of Diesel Engine Combustion by Varying Combustion Chamber Air Pressure

2020 ◽  
Vol 9 (2) ◽  
pp. 1866-1870
Keyword(s):  
Diesel Engine ◽  
Surface Temperature ◽  
Combustion Chamber ◽  
Experimental Work ◽  
Ignition Delay ◽  
Injection Pressure ◽  
Air Pressure ◽  
Solid Cone ◽  
Engine Combustion ◽  
Hot Surface

Complete and clean combustion is always desirable for better performance of engine and less emissions. An experimental work is carried in constant volume combustion chamber for getting conditions like diesel engine combustion to study the ignition delay characteristics of diesel engine combustion by varying combustion chamber air pressure. In this experimental work, air pressure of combustion chamber varied from 10 to 25 bar, hot surface temperature inside the combustion chamber varied from 350°C to 550°C and fuel injection pressures varied from 100 to 200 bar for hollow cone spray and solid cone spray . For this work a set-up is made in which the flame detection is done by digital storage oscilloscope using an optical method. The findings of the work suggests that combustion chamber air pressure and injection pressure are significantly varies the values of ignition delay at a particular hot surface temperature. It is also find that on increasing the values of combustion chamber air pressure and injection pressure, ignition delay values are decreases although the variation in ignition delay is less at higher injection pressure and combustion chamber air pressure.

Experimental investigations to predict optimistic biodiesel(s) and its optimistic operating conditions by varying ignition delay period and fuel spray pressures for lower emissions and better performance

2020 ◽  
Vol 234 (19) ◽  
pp. 3890-3902
Author(s):  
Vishal V Patil ◽  
Ranjit S Patil
Keyword(s):  
Methyl Ester ◽  
Ignition Delay ◽  
Seed Oil ◽  
Delay Period ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Rubber Seed Oil ◽  
Rubber Seed ◽  
Neem Seed Oil ◽  
Ignition Delay Period

In this study, different characteristics of sustainable renewable biodiesels (those have a high potential of their production worldwide and in India) were compared with the characteristics of neat diesel to determine optimistic biodiesel for the diesel engine at 250 bar spray pressure. Optimistic fuel gives a comparatively lower level of emissions and better performance than other selected fuels in the study. Rubber seed oil methyl ester was investigated as an optimistic fuel among the other selected fuels such as sunflower oil methyl ester, neem seed oil methyl ester, and neat diesel. To enhance the performance characteristics and to further decrease the level of emission characteristics of fuel ROME, further experiments were conducted at higher spray (injection) pressures of 500 bar, 625 bar, and 750 bar with varying ignition delay period via varying its spray timings such as 8°, 13°, 18°, 23°, 28°, and 33° before top dead center. Spray pressure 250 bar at 23° before top dead center was investigated as an optimistic operating condition where fuel rubber seed oil methyl ester gives negligible hydrocarbon emissions (0.019 g/kW h) while its nitrogen oxide (NOX) emissions were about 70% lesser than those observed with neat diesel, respectively.

scholarly journals Study on Diesel Low-Nitrogen or Nitrogen-Free Combustion Performance in Constant Volume Combustion Vessels and Contributory

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 923
Author(s):  
Qinming Tan ◽  
Yihuai Hu ◽  
Zhiwen Tan
Keyword(s):  
Ignition Delay ◽  
High Speed ◽  
Delay Period ◽  
Constant Volume ◽  
Combustion Performance ◽  
Combustion Flame ◽  
O2 Concentration ◽  
Constant Volume Combustion ◽  
Low Nitrogen ◽  
Ignition Delay Period

This paper studies the combustion performance of diesel in constant volume combustion vessels under different conditions of mixed low-nitrogen (O2 and N2) or non-nitrogen (O2 and CO2) in varying proportions. The high-speed camera is used to shoot the combustion flame in the constant volume combustion vessel. The process and morphology of the combustion flame are amplified in both time and space to study and analyze the effects of different compositions and concentrations in gases on the combustion performance of diesel and conduct a study on the contributory factors in the performance of diesel with no nitrogen. According to the study, in the condition of low nitrogen, the O2 concentration is more than 60%, the ignition delay period is shortened, the combustion flame is bright and slender, it spreads quickly, and the blue flame appears when the O2 concentration reaches 70%; While for nitrogen-free combustion, only when the O2 concentration reaches 30% is the combustion close to the air condition; when the O2 concentration reaches 40%, the combustion condition is optimized obviously and the combustion flame is relatively slender compared to the air working condition. Similarly, with the increase of the O2 concentration, the ignition delay period of nitrogen-free diesel is shortened, the duration is extended, and the combustion performance is optimized. In addition, when the O2 concentration reaches 50%, with the decrease of the initial temperature, the ignition delay period is prolonged, and the duration is shortened obviously. When the temperature is lower than 700 K, there is no ignition. The increase of the diesel injection pressure is beneficial to optimize the ignition performance of diesel non-nitrogen combustion and shorten its ignition delay period and combustion duration. Related research has important guiding significance to optimize nitrogen-free combustion technology, which produces no NOx of the diesel engine.

scholarly journals Effect of Cylinder Air Pressure and Hot Surface Temperature on Ignition Delay of Diesel Spray in a Constant Volume Combustion Chamber

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2565
Author(s):  
Mohammad Salman ◽  
Sung Chul Kim
Keyword(s):  
Combustion Chamber ◽  
Diesel Engines ◽  
Ignition Delay ◽  
Strong Dependence ◽  
Injection Pressure ◽  
Constant Volume ◽  
Fuel Additive ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber ◽  
Hot Surface

Present-day direct injection (DI) diesel engines with a high power density of displacement are not just promoting an expansion in the utilization of high-temperature resistant alloys in pistons yet, in addition, the expanded cylinder air pressures. When the temperature of the diesel engines piston exceeds a certain limit, it assumes a critical role at the start of sprays. The target of the present investigation was to look at the effects of cylinder air pressures (CAP) (10–25 bar) and high hot surface temperatures (HST) (350–450 °C). The ignition delay (ID) of pure diesel and that of diesel with Iftex clean system D (a cetane enhancer) are investigated experimentally. The experiments are performed by using a constant volume combustion chamber (CVCC) with a single hole pintle-type nozzle mounted on its head. A strong dependence of ID on the CAPs and HSTs was observed. A CAP of 25 bar is much inferior to the precombustion pressure of DI diesel engines; however, it is the case that combustion typical features are the same in spite of an inferior CAP, HST, and injection pressure. The ID tends to decrease to very small values with an increase in either of the two parameters. At a CAP of 25 bar, the measured ID of diesel with fuel additive is 45.8% lower than the pure diesel. Further, the ID of diesel with fuel additive at a 300 bar injection pressure and 25 bar CAP decreases at a rate of close to 0.2 ms/bar.

scholarly journals MODELING OF IGNITION DELAY PERIOD IN DIESEL ENGINE

2019 ◽  
Vol 0 (1) ◽  
pp. 34-38
Author(s):  
А. П. Марченко ◽  
І. В. Парсаданов ◽  
А. В. Савченко
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Delay Period ◽  
Ignition Delay Period

scholarly journals Experimental and numerical assessment of ignition delay period for pure diesel and biodiesel B20

2017 ◽  
Vol 252 ◽  
pp. 012068 ◽  
Author(s):  
Mohanad Aldhaidhawi ◽  
Marek Brabec ◽  
Miron Lucian ◽  
Radu Chiriac ◽  
Viorel Bădescu
Keyword(s):  
Ignition Delay ◽  
Delay Period ◽  
Numerical Assessment ◽  
Ignition Delay Period
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